An analysis of joint patterns in the Grampians Group rocks o£ Western Victoria has established that the dominant directions are north‐north‐west, east‐north‐east, west‐north‐west, north‐north‐east and north. The master joints are steeply‐dipping structures which formed after the sediments were lithified and folded. The joint‐formation is not genetically related to the folding and post‐dates the emplacement of the igneous intrusions. Joint orientation is independent of lithology and the sediments have reacted as a uniform mass to an applied stress.